If you run a marketing agency in Shoreditch or a web design studio in Manchester's Northern Quarter, you probably spend more on equipment than you think. New laptops for the team. A server upgrade. Office furniture when you move to bigger space. Even the coffee machine in the breakout area.
The annual investment allowance UK lets you deduct the full cost of most of those purchases from your profits in the year you buy them. That means less corporation tax to pay. And for agency founders, the current £1 million limit is generous enough to cover almost any single year of equipment spending.
Here is what you need to know, what qualifies, and where founders trip up.
What Is the Annual Investment Allowance?
The Annual Investment Allowance (AIA) is a type of capital allowance. Capital allowances let you deduct the cost of certain assets from your profits before you calculate tax. Without them, you would have to spread the deduction over many years through standard depreciation in your accounts.
The AIA is the most generous version. It gives you 100% tax relief in the year of purchase, up to a set limit. That limit is currently £1 million [1].
This applies to both sole traders and limited companies. If you are a limited company, the relief reduces your corporation tax bill. If you are a sole trader or partnership, it reduces your income tax bill [1].
The £1 million limit has been in place since 1 January 2019 and is confirmed until at least 31 March 2026 [2]. Before that, the limit fluctuated wildly. It was £500,000, then dropped to £25,000 in 2012, then went back up. The current stability is helpful for planning.
What Qualifies for the AIA?
The AIA covers most plant and machinery. That is a tax term, not a literal one. In practice, for an agency, it includes:
- Computers, laptops, monitors, and tablets
- Servers and networking equipment
- Office furniture (desks, chairs, shelving)
- Air conditioning and heating systems
- Catering equipment (the office kitchen)
- Fixtures such as lighting and bathroom fittings in a new office fit-out
- Certain building alterations needed to install plant and machinery
There are exclusions. Cars do not qualify for the AIA (they have their own capital allowance rules). Land and buildings do not qualify. Items used partly for private purposes are restricted. And assets you already owned before bringing them into your business do not qualify either [1].
If you buy something under a hire purchase contract, you can claim AIA on the full cost once you start using the item, not just the payments you have made so far [1]. That is useful if you are financing a larger purchase.
How the AIA Reduces Your Tax Bill
Let us use a real example. Say you run a 12-person digital agency billing £800k per year. Your profit after salaries and overheads is £120,000. Your corporation tax at 19% would be £22,800.
Now suppose you spend £40,000 on new laptops, monitors, and a server upgrade. Under the AIA, you deduct that full £40,000 from your £120,000 profit. Your taxable profit drops to £80,000. Your corporation tax falls to £15,200. You have saved £7,600 in tax.
That is the core benefit. The equipment costs you £40,000, but the net cash outlay after the tax saving is £32,400. The government effectively subsidises your investment.
If your profit is lower than the equipment cost, you can create a tax loss. That loss can be carried back or forward against other profits, depending on your structure.
What If Your Accounting Period Is Shorter Than 12 Months?
The £1 million limit is an annual figure. If your accounting period is shorter or longer, you must adjust it proportionally [1].
For example, if you start a new company and your first accounting period is 9 months, your AIA limit is 9/12 x £1,000,000 = £750,000. If you buy £800,000 of equipment in that period, only £750,000 qualifies for immediate relief. The remaining £50,000 goes into the general capital allowance pool and attracts relief at 18% or 6% per year.
This matters most for new agencies or companies changing their year-end. Check your accounting period length before making large purchases.
The Connected Companies Trap
Here is a trap that catches agency founders who own multiple companies. If two or more limited companies are controlled by the same person, they only get one AIA limit between them [1].
So if you own a marketing agency and a separate web design agency, and you control both, the £1 million limit is shared. You cannot claim £1 million on each.
The same applies to companies under common control of a group. If you are thinking of splitting your agency into multiple entities, factor this in. The AIA sharing rule can reduce the benefit.
For sole traders and partnerships, the rule is different. Each trade is separate, but if you run multiple businesses as a sole trader, you still only get one AIA limit.
Full Expensing: The Alternative for Companies
Since 1 April 2023, limited companies can also use full expensing. This gives 100% relief on most plant and machinery, with no cap [3]. It is effectively an unlimited AIA for companies, but only on main pool assets (not special rate assets like integral features or long-life assets).
Full expensing is a separate relief. You cannot claim both AIA and full expensing on the same asset. But for companies spending more than £1 million in a year, full expensing is the better option.
Sole traders and partnerships cannot use full expensing. They are limited to the AIA.
From 1 January 2026, a 40% first-year allowance will be available for qualifying plant and machinery purchased after that date [3]. This is less generous than full expensing but still useful.
When to Claim the AIA
You can only claim AIA in the period you bought the item [1]. You cannot delay the claim to a later year. If you buy equipment in March 2026, the relief must be claimed in the accounting period that includes March 2026.
This means timing matters. If you are close to your year-end and expect higher profits next year, you might want to delay a purchase. But if you need the equipment now, claim it now.
For hire purchase, the claim is triggered when you start using the asset, not when you sign the contract [1]. So if you order a server in March but it is not installed until May, the claim goes in the period covering May.
How to Claim the AIA
You claim the AIA through your tax return. For limited companies, it goes on the corporation tax return (CT600). For sole traders, it goes on the self-assessment return (SA100).
You will need to list the assets, their cost, and the amount of AIA you are claiming. Your accountant will handle this as part of your annual accounts preparation.
If you use accounting software like Xero or QuickBooks, your accountant will adjust the fixed asset register to reflect the AIA claim. The software typically posts depreciation automatically, but the tax adjustment is done outside the software.
If you are an agency founder doing your own accounts, be careful. The AIA is a tax adjustment, not an accounting adjustment. Your accounts will show depreciation, but your tax return will show the AIA instead. Getting this wrong can mean overpaying tax.
Common Mistakes Agency Founders Make
Claiming on cars. Cars do not qualify for the AIA. They have separate capital allowance rules based on CO2 emissions. If you buy a car through your agency, expect 18% or 6% writing-down allowances, not 100% relief.
Forgetting the connected companies rule. If you own multiple agencies, check whether they are under common control. If they are, the £1 million limit is shared. Plan purchases across the group accordingly.
Claiming on assets used privately. If you buy a laptop and use it 60% for business and 40% personally, you can only claim AIA on the business proportion. HMRC expects you to keep a log or have a clear basis for the split.
Missing the year-end timing. If your accounting period is 9 months, your AIA limit is £750,000. If you spend £800,000, £50,000 drops into the general pool. Plan your purchases around your year-end.
Not claiming at all. Many agency founders simply depreciate assets over 3-5 years in their accounts and never claim capital allowances on their tax return. That means they are paying more tax than necessary. If you have bought equipment in the last few years and did not claim AIA, you can usually go back and amend your return (within the time limits).
How Agency Founder Finance Can Help
We are ICAEW qualified accountants who work exclusively with agency founders. We see the AIA claim every day. It is one of the simplest ways to reduce your tax bill, but only if you get the timing and classification right.
If you are planning a significant equipment purchase, or if you think you may have missed AIA claims in previous years, get in touch. We can review your fixed asset register and your past tax returns to make sure you are claiming everything you are entitled to.
We also work with agencies across all sectors, including marketing agencies, digital agencies, and creative agencies. The AIA rules apply the same way regardless of your specialism, but the assets you buy will differ. We can advise on what qualifies in your specific context.
Final Thoughts
The annual investment allowance UK is a straightforward tax relief that can save your agency thousands of pounds. The £1 million limit is generous enough for almost any agency. The rules are clear. The main risks are timing, connected companies, and asset classification.
If you are buying equipment for your agency, claim the AIA. Do not let the tax relief sit on the table.
For more on agency tax planning, read our tax and compliance blog or our agency finance essentials series.
Sources
- gov.uk: Claim capital allowances: Annual investment allowance - GOV.UK
- icaew.com: Capital allowances | Tax - ICAEW.com
- aka.hmrc.gov.uk: Claim capital allowances: Overview - GOV.UK